Beirut: Al-Qaeda's Syrian affiliate has offered to release three Lebanese soldiers in exchange for an ex-wife of the leader of the jihadist Islamic State group and four other female prisoners.

Al-Nusra Front, which along with IS has held 25 Lebanese soldiers and policemen hostage for almost a year, issued the offer in a statement aired on Lebanon's MTV television last night.

"If five of our sisters leave prison... We will hand over three soldiers in exchange," said Abu Malek al-Shami, Al-Nusra's "emir" in the Syrian region of Qalamun bordering Lebanon.

Among the five hostages he named was Saja al-Dulaimi, who was arrested in Lebanon in December and is a former wife of IS leader Abu Bakr al-Baghdadi, as well as a wife of an Al-Nusra leader.

Dulaimi's background is complicated as she reportedly belongs to a tribe that straddles Syria and Iraq and she was said to have been closer to Al-Nusra than her ex-husband's rival jihadists at the time of her arrest.

Shami's face was not shown in the interview, which MTV conducted as part of an arranged visit by family members to loved ones held by Al-Nusra in what it called "a cave in the Qalamun mountains".

The channel showed footage of the three-hour reunion between parents, spouses and even children of the hostages, many of them unable to hold back their tears.

The hostages, all with long beards, appeared in healthy condition inside a tent.

Sixteen of the 25 Lebanese soldiers and policemen who were taken hostage near the border with Syria in August 2014 are in the hands of Al-Nusra.

The rest are held by Baghdadi's Islamic State group.

Since their capture, Al-Nusra and IS have repeatedly made demands for the soldiers' release, seeking the release of Islamist prisoners or the withdrawal of Lebanon's Hezbollah movement from the Syrian conflict.

The powerful Shiite militia, which is backed by Iran, is fighting alongside forces loyal to President Bashar al-Assad in the civil war that has claimed more than 230,000 lives since it erupted in 2011.